G_CALLBACK (on_button_press_event), &game);
g_signal_connect (G_OBJECT (window), "button_release_event",
G_CALLBACK (on_button_release_event), &game);
G_CALLBACK (on_button_press_event), &game);
g_signal_connect (G_OBJECT (window), "button_release_event",
G_CALLBACK (on_button_release_event), &game);